1. Field of the Invention
The present invention refers to a tool storing magazine incorporating a tool-change apparatus adapted to remove a tool from the magazine and to transport the tool into a workpiece machining apparatus, and adapted to remove a tool from the workpiece machining apparatus and to transport the tool back to the tool storing magazine, respectively. Further, the invention refers to a workpeice storing magazine incorporating a workpeice-change apparatus adapted to remove a workpiece from the magazine and to transport the workpeice into a machining apparatus, and adapted to remove a workpeice from the machining apparatus and to transport the workpeice back to the workpiece storing magazine. Still further, the invention refers to the use of the tool storing magazine incorporating a tool-change apparatus of the kind referred to hereinabove for inserting and removing electrodes of an electro-erosive machining apparatus, the central axis of the inserted electrodes running in vertical or horizontal direction. Finally, the invention refers to the use of the workpiece storing magazine incorporating a workpiece-change aparatus of the kind referred to hereinabove for feeding workpieces to and removing workpieces from, respectively, an electro-erosive machining apparatus, the central axis of the workpieces received in the apparatus running in vertical or horizontal direction.
Many machining operation of a single workpiece require that the the tool used to machine the workpiece has to be changed several times in the course of the machining operation, particularly if the control of the machining apparatus is performed more or less automatically; such a machining apparatus is in a position to preform a plurality of machining operations on a single workpiece in sequence. In order not to disturb or interrupt this automatically running machining operation, automatically operating tool-change means have been developed which can be controlled by the same control means which are used for controlling the automatic operation of the machining apparatus.
These problems are particularly present in connection with the electro-erosive machining of workpieces because such machining is a relatively slowly progressing machining operation. Thus, it is most desirable to automate this kind of machining operation as fully as possible.
2. Prior Art
In the prior art are known, for instance, electro-erosive machining apparatus incorporating an electrode-change device which includes an electrode magazine in the form of an endless, continuously running chain-like storage member. Further, a gripping arm is provided and operated to grasp a slected electrode and to insert it into the electro-erosive machining apparatus, and to remove the electrode from the electro-erosive machining apparatus and to put it back into the storage member, respectively. In order to ensure that the selected electrode is taken out of the magazine and that the electrode removed from the machining apparatus is put back to its proper position in the magzine, respectively, a magazine of the kind referred to above must be driven to run along a continuous path until the selected electrode and the proper storage position, respectively, comes to a location where it can be reached by means of the above mentioned gripping arm.
The main disadvantage of this kind of electrode-change apparatus are, on the one hand, the large space requirement and, on the other hand, the comparatively slow access speed, particularly if a large number of electrodes are in the magazine which must be ready for immediate access.
In order to avoid these disadvantages, it has been proposed to use a tool magazine comprising a plurality of essentially disc-shaped tool support members which are rotatable around a first axis of rotation, the tools being arranged along the periphery of the tool support members. Further, there is provided a transport arm which is pivotal around a second axis of rotation and located in a certain distance from the first axis of rotation, said transport arm being adapted to grasp the tools, to remove them from the magazine and to insert them into the machining apparatus and vice versa. Such a tool magazine requires less space and has an improved access speed.
However, there is the disadvantage that such a tool magazine is not universally usable. On the one hand, modern machining centres including electro-erosive machining apparatus often make use of more than one reference axis; for instance, an electrode or a workpiece has to be mounted with its axis running either in vertical or in horizontal direction. On the other hand, the need may arise to machine a plurality of workpieces sequentially with a single tool, e.g. with the same electrode, which consequently has not to be changed.